This invention relates to manometers and more particularly to a manometer adapted to contain and control mercury spillage in the laboratory.
Manometer systems for measuring changes of gas pressures are well-known. Prior art devices generally comprise a U-tube, constructed of a glass tubing having one end open to the atmosphere, and the other to the region where the pressure is to be measured. Another type has one end of the U-tube to the pressure region and the other end is sealed off after evacuation. Where the pressure is different from atmospheric, the liquid with which the manometer is partially filled will stand higher in one leg of the tube than in the other. However, sudden pressure surges during testing can frequently be of sufficient magnitude to blow mercury out of the apparatus. If the end of the manometer is sealed the sudden impact against the seal end of the glass tubing would strike with sufficient force to break the tubing and cause mercury spillage on to personnel, equipment and the laboratory area. Since mercury is toxic, it is a peril to personnel and it must be properly controlled preferably within the containing unit. In addition certain U-type manometers have the disadvantage of the weight of the mercury resting on one arm of the manometer causing a weak point at the base of the U-tube.